Retracting Caliper Pistons, How to? Options

[Vince-Noir]

My new rear discs are on and the calipers are off waiting for me to retract the pistons before i replace the pads, but i have no idea how to retract the pistons on my 98 GT (3SGE). In fact they look fully extended!

Can anyone tell me how to do this please?

Many thanks

[alltracman78]

Two problems.

1-When you pushed the piston back in, if brake fluid leaked out past the piston, the piston seal is leaking.
It might or might not leak when the caliper is back on the car and you use the brakes.
If it does leak, you won't have much braking force at all.

2-You left the cap off the master cylinder, which pretty much means ALL your brake fluid is junk.
This is why:
Your brakes get really hot when you use them. The harder you brake the hotter they get. This heats up the brake fluid in the line a lot. Brake fluid is designed with a very high boiling point [tells you on the bottle of fluid] so it won't boil from the heat. If it boils, you lose braking force.
Water on the other hand boils at a relatively cool 212*F.
What does water have to do with brake fluid?
Brake fluid absorbs water. Really bad.
Imagine the brake fluid is Michael Jackson and the water is a cute 8 yr old boy. It can't stay away.

So, while the brake fluid might not boil when you brake hard, the water will. Which once again makes you lose brake force.

My suggestion is to
replace the caliper
flush your brake fluid COMPLETELY
This can be done with a mighty vac or having one person pump the pedal while the other loosens the bleed port. The second one will take a while.